Metal working machine



Filed April 21 1927 4 Sheets-Sheet P 1932- J M. CHRISTMAN- 1,876,204

METAL WORKING MACHINE Filed April 21. 1927 4 Sheets-Sheet 2 ,5 aw- 78L96 .20 21 2g Lin/n my Sept. 6, 1.932. J. M. CHRISTMAN 1,876,204.

METAL WORKINGv MACHINE P 1932- Y J. M. CHRISTMAN 1,876,204

METAL WORKING MACHINE Filed April 21. 1927 4 Sheets-Sheet 4 K WFmabtozwuag Joint at.

Patented Sept. 6, 1932 eanes stares CO'MPANY, 01E DETEQIT, MICHIGAN, AGQEPQRATION OF MICHIGAN am orr cs CHRISTMAN, or DETROIT, MICHIGAN,ASSIGNOR To rAoKARnMoToR OAR METAL WORKING MACHINE I Applicationfi1ed-Apri1 21 This invention relates "to metal working machines, andwhile capable'of general use, is particularly adapted for machining orprofiling the walls of compression recesses formed in cylinder heads forhydrocarbon motors.

vCylinder heads for hydrocarbon motors have heretofore beencast withcompression recesses therein of tapered depth, and it frequently happensthat irregularities occur in the contours of the compression recess suchas to produce variation 'incompre-ssion of the several cylinders of thehydrocarbon-motor with the resulting defective operation of the latter.It has therefore been proposed to machine the walls or surfaces of thetapered compression recesses uniformly to produce uniform compression inthe cylinders of the hydrocarbon motor and the principal object of thepresent invention is to provide an improved mechanism for profiling acompression recess and one which is adapted to profile a taperedcompression recess which is undercut at its deeper portion around thevalves and has certain recognized advances over tapered compressionrecesses heretofore employed. i I

Other objects of this invention are to provide an improved mechanismwhich embodies a swinging work holder or cradle and swinging millscooperating therewith to machine the entire surfaces of the taperedcompression recesses; which'includes an arrangement of swiveled mills orcutters and a swinging cyl inder head support that enables the walls ofthe tapered recesses, to be undercut at the deeper portions thereofwhich insures a positive and continuous drive for the mills or cuttersduring their swinging movement, through the medium of flexible drivingconnections for said cutters with a source of power; and which is asimply constructed, expeditious, and highly efficient mechanism formachining the walls of tapered compres-- sion recesses or for profilingvarious other classes of work.

in order to more clearly understand this invention, reference may be hadto the ac.- companyingdrawings which illustrate one 1927. Serial No.185,626.

embodiment of the inventive idea and whereinz- 5 Fig. 1 is a detailperspective view of the machine, with parts omitted for purposes ofclearer illustration;

Fig. 2 is a side elevation of the machine shown in-Fig. 1; v I

Fig. 3 is a vertical sectional View on the line 33 of Fig. 1;

Fig. 4c is a fragmentary bottom plan View of a cylinder head, showingdiagrammatn. cally the machining and undercutting operations;

Figs. 5 and 6 are sectlonal details, showing the manner of machining andundercutting,

the wall" of a tapered compression recess in the direction ofits length;and

Fig. 7 is a sectional detail, showing the manner of machining andundercutting the wall of the recess laterally'thereof.

Referring to the drawings, wherein like reference characters designatelike parts throughout the several views, 5 indicates the base of themachine provided at the rear thereof with a vertical column 6. Extendingforwardly from the column 6 is a head 7 that overhangs a table 8 at thetop of the base 5' (Figs. 1, 2 and The machine'may Fig. 1, extendshorizontally acrossthe Inachine to the opposite sides thereof, andconstitutes the main source of power for im--- parting motion tothevarious movable instrumentalitles herelnaftcr described. Fixed .onthe driven shaft- 15 is a bevel gear 18 that meshes with a similar gear19 rigidly secured on one end of a shaft 20 disposed substantially atright angles to the shaft 15 and journaledin suitablebearings 21, 21' onthe upper surface of the head 7. The opposite end of the shaft 20 hasfixed thereon a bevel gear 22 that meshes with a similar gear 23 rigidlysecured on the upper end of a vertical shaft 24 that is ournaled insuitable bearings 25, 25'on the column 6 and projects clownwardlytherein at one side of the machine.

Fixed on the lower end of the shaft 24 is a bevel gear 26 that mesheswith a similar gear 2'? that is keyed or otherwise rigidly secured on ashaft 28 journaled in suitable bearings in the column 6 and extendingtherethrough to the opposite sides of the machine. This shaft 28 hasfixed thereon a cam 29 which, from the above described drivingconnections, serves to swing a work support or cradle 30 toward therearand front of the machine through the medium of the following devices.Pivotally mounted at 31 on a bracket .32 within the column 6 is an arm33 provided intermediate its ends with a roller 34 that engages in thegroove 35 of cam 29. Pivotally connected at 36 with the free end of thearm 33 is a rod 37 that is also pivotally connected at 38 with an ear orlug 39 that projects rearwardly from the cradle 30. The

rod 37, as clearly shown in Fig. 3, extends outwardly through a suitableopening in column 6 and is preferably made in two parts connectedtogether by a turnbuckle 40 or other suitable device for adjusting thelength of said rod and thereby regulating the amount of swingingmovement imparted to the cradle 30 by the cam 29.

The cradle .30 is preferably mounted to swing rearwardly and forwardlyof the machine on an axis substantially parallel with that of the drivenshaft 15 and for this purpose the side walls 41, 41 of said cradle areprovided with trunnions 42, 42 journaled in bearings provided bybrackets 43, 43 and bearing blocks 44, 44 bolted or otherwise suitablysecured at 45, 45 to the brackets 43, 43 (Fig. 1). The brackets 43, 43are secured to or formed integrally with a saddle 46 (Fig. 3) thatprojects forwardly from the head 7 at the lower part thereof, and saidbrackets, together with the blocks 44, 44, facilitate the mounting ofthe cradle 30 in or removal of the same from, the bearings provided bythe brackets 43 43 and the blocks 44. 44.

The work holder or cradle 30 has bolted or otherwise suitably secured tothe top there of a frame 47 through an opening 48 of which a pluralityof rose end mills or cutters 49, 49 extend to engage with the work to bemachined or profiled. As herein disclosed the work consists of acylinder head 50 that is supported in the cradle 30 in an invertedposition against the frame 4? and provided with tapered compressionrecesses 51, 51, the walls of which are machined and undercut by themills or cutters 49, 49 in a manner to be hereinafter described. Thecylinder head 50 is placed within the cradle through the front thereofwhich is open for this purpose, said cylinder head preferably beingengaged with pins 52 and 5.3 on the cradle and clamped therein againstthe frame 47 by a clamping head 54.

The clamping head 54 is rotatably secured on the upper end of a verticalscrew shaft 55 threaded through a suitable opening in the bottom 56 ofthe cradle and adjustable up and down therein through the medium of ahand wheel 57 rotatably mounted on the bottom 56 of the cradle The hand.wheel 57 is retained against displacement by engagement with. a groove58 formed on the rear wall 59 of the cradle 30. During movement of theshaft 55 and the clamping head 54, rotation of the latter is preventedby a pin 60 that projects rearwardly from said head through a suitableopening formed in the rear wall 59 of said cradle. In order to preventundue strain on the top and bottom walls of the cradle by the clampingof the work therein, said cradle is provided with a strut bar 61arranged to extend across the open front of the cradle and pivoted at 62to the top thereof so that said bar may be swung upwardly out of the waywhen the work is .eing placed in the cradle. After the work has beenpositioned in the cradle, the bar 61 is swung downwardly and secured tothe bottom wall 56 of the cradle by a block 63 adj ustably mounted onthe lower end of the bar 61 and adapted to be connected with the cradle36 by a pin 64 or other suitable fastening means. After the lower end ofthe bar has been secured to the bottom of the cradle, the work isclamped in said cradle as above described.

V1 ith the parts in the full line positions shown in the drawings, thework is ready for the machining and undercutting operations performed bysimultaneously swinging the cradle 30, driving the tools or cutters 49,49, and swinging the latter on axes extending transversely of the pathof swinging movemerit of the cradle and the cylinder head carriedthereby. The mechanism for swinging the cradle has already beendescribed, and the mechanism for driving the cutters and swinging; themin the manner stated is preferably constituted by the followinginstrumental ties. The mills or cutters 49, 49, at the beginning of themachining and undercutting operations, preferably engage the walls orsurfaces of the compression recesses 51, 51, at the shallower endsthereof. These mills or cutters are rotatably mounted in tool holders65, 65 adjustably mounted in any desired manner on swiveled heads orcarriers 66, 66 so as to provide for the depth of cut to made in thecompression recesses and, if desired. for movement of the mills orcutters into and out of said recesses through the opening 43 in frame47. As herein shown, the tool holders lit",

' v or cutters surface provided by the front face of the saddle46, andeach trunnion 6? is provided on the end thereof opposite that carryingthe 'head'66 with a retaining nut 68 for preventing displacement of theswiveledhead from its bearing in the saddle 46.

The heads 66,66 with the driven mills or cutters 49, 49 tl ereon areswung siniultaneously by any suitable means such as a rod 69 pivotallyconnected at 70, 70 with said heads and reciprocated by ,a link 71 oneend of which is pivotally connected at 72 with the rod 69. The oppositeend of the link 71 is pivotally connected at 73 with the free end of anarm 7 4 pivoted at 75 on the overhanging head 7 and carrying a roller 76 that engages in a groove 7? of a cam 7 8. The connection for the link71 WlL-ll the arm 4 is preferably constituted by the pivot 73thatextends through a slot 73 in the arm 7 4 and is adjusted in sa-idslot bya set screw 78" to eliminate variation in cutting by the mills 49, 49,when they wear down or are ground. The cam 78 is fixed on the front endof a shaft '59 journaled insuitable hearings on the head '1" andenclosed in'a housing 80 secured thereto, Fixed on the rear end of theshaft 79 is a'worm wheel- 81 that meshes with a worm 82 rigidly securedon the upper end'of a vertical shaft 83 disposed at the side of themachine opposite that carrying the shaft 24. The worm wheel 81,worm 82,and the upper end of the shaft 83, are enclosed in an enlarged portion84 of the housing 80, the lower end of the shaft 83 projectinginto ahousing 85 secured to the adjacent side of the column 6 near the 7bottom thereof. Fixed on the lower end of the shaft 83 is a worm 86 thatmeshes with a worm wheel 87 keyed orotherwiserigidly secured on theshaft 28 which also extends into the housing 85. ft will thus appearthat the shaft 28 through the shaft 83, shaft 80, and gearing connectingthe same, serves to drive thecam 7 8 as well as the devices for swingingthe cradle 30.

During swinging movement of the heads 66, 66 and the cradle 39,, therose'end mills or cutters 49, 49 are driven by means that preferablyinclude flexible connections providing for swinging movement of theheads 66, 66 and cutters 49, 49 as the latter are rotated. As hereinshown, these. flexible corn.

ne'ctions are comprised by telescoping shafts,

the parts 88, 88 and 89, 89 of which rotate together and slide onewithin the other as the heads 66,66 are oscillated. The parts 88, 88 ofthe telescoping shafts are connected by universal joints 90, 90 withtool spindles 91, 91 that carry the mills or cutters 49, 49

and are journaled in the adjustable tool holders 65, 65. vThe parts 89,89 of said telescoping shafts are connected by universal joints 92, 92with the lower ends of stub shafts93, 98 that are journaled in suitablebearings in a forwardly extendin part 94 of the'saddle 17. Fixed on theupper end of the stub shafts 93, 93 are worm wheels 95, 95 which meshwith a worm'96 fired on the shaft 15 and thus serve to drive the millsor cutters 49, 49 through the described flexible connections.

In the operation of the machine, the mills or cutters 49, '49 areengaged with the walls of the tapered compression recesses 51, 51 atwhich timethe parts of the machine occupy the full line positions shownin the drawings. The machine is then started, as by throwing in a clutch(not shown) interposed between the pulley 14 and the driven shaft 15.There after, the shaft 15 through thedriving connections therefor withthe cradle 30 and the mills or cutters 49, 49, rotates said cutters andswings the cradle. During swinging movement of the cradle 30 and thecylinder head 59 thereon, swinging movement is imparted to the drivenmills or cutters 49, 49, transversely of the path of swinging movementof the cylinder head 50, by the cam 78 and connections therefrom withthe swiveled heads 66,66. By these movements of the cutters and thecylinder head, the walls of the tapered compression recesses 51, 51 aremas chined over the entire surfaces thereof and are undercut at thedeeper portions of the recesses. in the machining and unde'rcut tingoperations the mills or cutters 49, 49 follow closed paths conformingwith the margins ofthe compression recesses and identical inconfiguration. One of these paths is illustrated diagrammatically inFig.1

4' where A represents the traverse of the axis of the cutter, and B, C,D, E, F, and Grepresent, in the order named, positions successivelyoccupied by the cutter as the latter and the work swing relatively inthe manner stated. The undercutting preferably begins at the position C,ends at the position F, and is greatest at the positions 1) and E whereare located the deeper portions of the recess that lay over the valveswhen the head 50 is secured on the internal combustion engine abo e thecylinders thereof.

It will thus appear that the machining and undercutting of the walls ofthe tapered compression recesseswith the mills or cutters 49, 49,results from motion having two components which are circular arcsdisposed in intersecting planes that preferably extend substantially atright angle to each other. Une of these components is obtained by thefore and aft swing of the cradle 30 relative to the cutters which, asillustrated diagrammatically in Figures 5 and 6, machine the walls ofthe tapered compression recesses in the direction of the lengthsthereof. The other component is obtained by the swinging movement of thecutters which, as shown diagrammatically in Fig. 7, also machine theWalls of the tapered compression recesses laterally thereof.

In some types of cylinder heads, the compression recesses thereof havereentrant portions such as indicated at H, H, l). in this case, thegroove 35 of the cam 29 may be provided with a lobe 96 3) that impartsan additional motion to the cradle 30 so that the mills or cutters 4:9,49 follow the margins of the reentrant portions H, H, thus insuringaccurate machining of the surfaces thereof. After the machining andundercutting operations have been completed, the clutch above referredto is thrown out to stop the machine so that the parts thereof occupythe full line positions shown in the drawings. in this position of theparts, the mills or cutters 49, 4-9 are, as when initially engaged withthe work, disposed in the shallower portions of the tapered compressionrecesses 51, 51. The cylinder head 50 may then be readily removed fromthe cradle 30 by unclamping the head 54 and swinging the strut bar 61upwardly about 3 its pivot 62.

llt is to be expressly understood that mechanism constructed inaccordance with the present invention may be employed not only formachining cylinder heads but for machining or profiling other classes ofwork, and that while one embodiment of the inventive idea has beenillustrated and described herein with more or less detail, the inventionis not limited to such embodiment, or otherwise than by the terms of theappended claims.

W hat is claimed is 1. lln a machine of the character described, a workholder arranged for oscillating movement and adapted to support worktherein, means for oscillating the work holder and the work, a drivencuttin tool extending in the work holder for engagement with the workand arranged to oscillate in the work holder about an axis extendingtransversely of the axis of oscillation of said work holder, and meansfor oscillating the driven cutting tool within the work holder duringoscillating movement of the latter and the work, whereby said tool cutsinto and machines said work.

2. In a machine of the character described, a driven cutting toolarranged for oscillating movement, means for oscillating the drivencutting tool, a work holder in which the driven cutting tool extends andoscillates, means supporting said work holder for oscillating movementabout an axis extending transversely of the axis of oscillation of thedriven cutting tool, and means for oscillating the work holder duringoscillating movement of the driven cutting tool therein, whereby saidtool cuts into and machines work supported within the work holder andoscillating therewith.

3. In a machine of the character described, a work holder arranged foroscillating movement, means for oscillating the work holder, a toolholder arranged for oscillating movement about an axis extendingtransversely of the axis of oscillation of the work holder, a drivencutting tool on the tool holder extending therefrom into the work holderto oscillate therein, and means for oscillating said tool holder and thedriven cutting tool dur ing oscillating movement of the Work holder,whereby said tool cuts into and machines work supported in the workholder and oscillating therewith.

4:. In a machine of the character described, a tool holder arranged foroscillating movement, a driven cutting tool on the tool holder, meansfor oscillating the tool holder and the driven cutting tool, a workholder into which the driven cutting tool extends from the tool holder,means supporting the work holder for oscillating movement about an axisextending transversely of the axis of oscillation of the tool holder andthe driven cutting tool, and means for oscillating the work holderduring oscillating movement of said tool holder and the driven cuttingtool, whereby said tool cuts into and machines work supported in thework holder and oscillating therewith.

5. In a machine of the character described, a cradle and a drivencutting tool extending into said cradle, both said cradle and said toolbeing arranged for oscillating movement each transversely of the other,a driven shaft, a flexible driving connection between the driven shaftand the driven cutting tool and providing for oscillating movement ofthe cutting tool in the cradle while said tool is being driven by saidshaft, and means for automatically and simultaneously oscillating thecradle and the driven cutting tool, whereby said tool cuts into andprofiles work engaged therewith and carried in said cradle.

6. In a machine of the character described, a work holder and a drivencutting tool there in both arranged for oscillating movement eachtransversly of the other, a driven shaft, a telescopic shaft, universalconnections for the parts of the telescopic shaft with the driven shaftand the driven cutting tool and providing for oscillating movement ofthe latter in the work holder while said tool is being driven by saidshaft, and means for simultaneously oscillating the work holder and thedriven cutting tool therein, whereby said tool cuts into and machineswork supare ill;

ported within said work holder and oscillating therewith. v

7. In a machine of the character described,

a cradle arranged for oscillating movement, I

within the latter, and means for simultanea tool carrying head arrangedto oscillate transversely of the path of oscillating move- 'ment ofthecradle, a cutting tool rotatably' mounted on the tool carrying head andeX- tending therefrom into the cradle to rotate and oscillate therein, adriven shaft for rotating the cutting tool, a flexible drivingconnection between the driven shaft and the cutting tool and providingfor oscillating move ment thereof in the cradle while said tool is beingrotated by said shaft and said connection, and means for simultaneouslyoscillating the cradle and the tool carrying head transversely of eachother, whereby said tool cuts into and machines work supported in saidcradle-and oscillating therewith.

8. In a machine of the character described, an oscillating cradle, aswiveled head arranged to oscillate transversely of the path ofoscillating movement of the cradle, a tool holder adjustably mounted onthe swiveled head and carrying a rotatable cutting tool extending in thecradle and adapted to oscillate with said head, means for driving thecutting tool providing for oscillating movement thereof in the cradle,and means for automatically and simultaneously oscillating saidelements, whereby the tool cuts into and profiles work engaged therewithand secured in the cradle. I

9. In a machine of the character described, a pivoted Work holder, atool carrying head swiveled atone side to swing transversely of thedirection of swinging movement or the work holder, a driven cutting toolrotatahly mounted on the opposite side oi the tool carrying head andadapted to engage work supported on said work holder, means for swingingthe swiveled tool carrying head and the driven cutting tool, and meansfor swinging the work holder and the workduring swinging movement of theswiveled head and the driven cutting tool, whereby" said tool cuts intoand machines said work.

10. In a machine of the character described, ahollow work holdertrunnioned thereon, means for swinging the hollow work holder, aswiveled tool carrying head arranged to swing transversely of the pathof swinging movement of the work holder and simultaneously therewith, adriven cutting tool mounted on said swiveled head to swing therewith.and extending in thehollow work holder to cut'into and profile Worktherein during said swinging movements, and means for swinging theswiveled head comprising a driven carn'and a member reciprocated therebyand operatively connected with said swiv- ,'eled head. 7

11. In a machine of the character described, an oscillating work holder,means for imparting oscillating motion thereto, a plurality of drivencutting toolsarranged to oscillate transversely of the path ofoscillating movement of the work holder and extending ously oscillatingsaid tools in the work holder during oscillating movement of said workllOlQcl, whereby the tools cut into and profile work engaged therewithand carried in the work holder.

12., In a machine of the character described,

an oscillating work holder, means for imlate transversely of the path ofoscillatingmovement of the work holder, a driven cutting tool on each ofsaid heads extending therefrom into the work holder and adapted to cutinto and profile work supported therein during oscillating movement ofthe work holder, means for driving the tools providing for oscillatingmovement of the same with the tool carrying heads and within the workholder, and means for simultaneously oscillating said heads and thedriven tools carried thereby.

13. In a machine'oif the c haracterdescribed, a pivotally mountedworkholder,means for impartingswinging motion thereto, a pluralitytool'carrying heads arranged to swing transversely of the path ofswinging movement of the work holder, a cutting tool rotatably mountedon each of said heads and extending therefrom into theework holder'toswing therein and engage work supported within the same, a drivenshaft,'fiexible driving connections for said shaft with the toolsadapted to rotate the same and providing for swinging movement or" saidtools with the swinging heads and within the work holder, and means forsimultaneously swinging the tool carrying heads during swinging move- 7ment of the work holder whereby several portions of the work carried inthe latter in em gagement with the driven tools are simultaneously cutor machined and profiled thereby.

l-fl. In a machine of the character described,

an oscillating work holder adapted to support a cylinder head thereinhaving tapered compression recesses, means for swinging the undercutsaid walls at the deeper portions of the recesses. 15. In a machine'ofthe character described,

an oscillating work holder adapted to support a cylinder head thereinhaving tapered compression recesses, means for swinging the work holderand said cylinder head, a plurality of devices swiveled on the machineto swing transversely of the path of swinging movement of the workholder and the cylinder head, a corresponding number of driven mills orcutters carried by said swiveled devices and extending therefrom intothe work holder to swing therein and engage the walls of the taperedcompression recesses, and means for simultaneously swinging saidswiveled devices during swinging movement of the work holder and thecylinder head, whereby said mills or cutters out or machine the walls ofthe tapered compression recesses and undercut said walls at the deeperportions of the recesses.

16. In a machine of the character described, a work holder trunnionedthereon adapted to support a cylinder head having tapered compressionrecesses therein, means for swinging the work holder and said cylinderread, a plurality of driven mills or cutters arranged to swingtransversely of the path of swinging movement of the cylinder head andengage the walls of the tapered compression recesses, a driven shaft, aplurality of telescoping shafts, universal connections for the parts ofeach telescoping shaft with the driven shaft and one of said mills orcutters, and means for simultaneously swinging the driven mills orcutters during swinging movement of the cylinder head, whereby the millsor cutters machine the walls of the tapered compression recesses andundercut said walls at the deeper portions of the recesses.

17. line machine of the character described, a work holder trunnionedthereon adapted to support a cylinder head having tapered compressionrecesses therein, means for swinging the work holder and said cylinderhead, a plurality of devices swiveled on the machine to swingtransversely of the path of swinging movement of the work holder and thecylinder head, a plurality of driven mills or cutters each mounted onone of said swiveled devices and adapted to engage the wall of one ofthe tapered compression recesses, a reciproeating element connected witheach of the swiveled devices for simultaneously swinging them to rockthe driven mills or cutt rsi the tapered compression recesses, and a camor reciprocatingsaid element during swinging movement of the work holderand cylinder head, whereby the mills or cutters machine the walls of thecompression recesses and undercut said walls at the deeper portions ofthe recesses.

18. In a machine of the character described, a work holder forsupporting a cylinder head having compression recesses therein oftapered depth, means supporting said work holder for swinging movementrearwardly tapered compression recesses and mounted to 1 swing towardopposite sides of the machine across the path of swinging movement ofthe work holder and the cylinder head, and means for swinging the drivenmills or cutters simultaneously during swinging movement of the workholder and cylinder head, whereby said mills or cutters simultaneouslymachine the walls of the tapered compression recesses and undercut saidwalls at the deeper portions of the recesses.

19. In a machine of the character described, a cradle arranged at thefront thereof to support a cylinder head having compression recessestherein of tapered depth, bearings for said cradle providing forswinging movement of the same rearwardly and forwardly of the machine,means for swinging the cradle with the cylinder head secured thereon, aplurality of driven mills or cutters adapted to engage the walls of thetapered compression recesses and arranged in line across the front ofthe machine for swinging movement laterally of the path of swingingmovement of the cradle and the cylinder head, and means for swinging thedriven mills or cu tters simultaneously t during swinging movement ofthe cradle and cylinder head, whereby said mills or cutters machine thewalls of the tapered compression recesses and undercut said Walls at thedeeper portions of the recesses.

20. In a machine of the character described, a'column or the like havingan overhanging head, a cradle trunnioned on said head for swingingmovement and adapted to support a cylinder head having compressionrecesses therein of tapered depth, means for swinging the cradle and thecylinder head thereon, a plurality of driven mills or cutters adapted toengage the walls of said recesses and mounted on the head of said columnfor swinging movement laterally of the path of swinging movement of thecradle and the cylinder head, and means for swinging the driven mills orcutters simultaneously during swinging movement of the cradle andcylinder head, whereby said mills or cutters machine the walls of thetapered compression recesses and undercut said walls at the deeperportions of the recesses.

21. In a machine of the character described, a work holder forsupporting a cylinder head having compression recesses therein oftapered depth, means supporting said, work holder for swinging movementrearwarclly and forwardly of the machine, a plurality of tool-carryingheads mounted on said means to swing toward opposite sides of themachine laterally of the path of swinging movement of the work holderand the cylinder head, a driven mill or cutter mounted simultaneouslyduring swin ing movementof the work holder and cylinder head, wherebythe driven mills or cutters machine the walls of the tapered compressionrecesses and undercut said walls at the deeper portions of the recesses.s

v 22. In a machine of the character described, a work holder forsupporting a cylinder head having compression recesses'therein oftapered depth, means supporting said work holder for swinging movementvrearwardly and forwardly of the machine, means for swinging the workholder and the cylinder head thereon, a plurality of tool-carrying headsswiveled on said first named means to swing toward opposite sides of themachine laterally of the path of swinging movement of the work holderand the cylinderhead, a tool holder mounted on each swiveled head toswing therewith and adjustable lengthwise or said swiveled head, adriven mill or cutter rotatably mounted on each tool holder and adaptedto engage the wall of one of the tapered compression recesses, and meansfor swinging the swivelled heads simultaneously during swinging movementoi 'the work holder and cylinder head, whereby the driven mills orcutters machine the walls of the tapered compression recesses andundercut said walls at the deeper portions of the recesses.

23. In a machine of the character described, a column or the like havingan overhanging head projecting thereltrom, a cradle mounted on said headto depend therefrom and swing-toward and away from the column, a driventool mounted on the overhang ing head to extend downwardly therefrominto the cradle and swing transversely or" the path of swinging movementof the latter and means for swinging the cradle and the driven tooltherein simultaneously, whereby said tool profiles work engagedtherewith and carried in the cradle.

24,-. In a machine of the character de scribed, a column or the likehaving an overhanging head projecting therefrom, a cradle mounted onsaid head to depend therefrom and swing toward and away from the column,

a tool carrier swiveledron the overhanging head to swing transversely ofthe path of swinging movement of the cradle, a driven tool mounted onsaid tool carrier and ex-v tending downwardly into the cradle, and meansfor swinging the cradle and the swiveled tool carrying headsimultaneously, whereby the driven tool profiles work engaged therewithand carried in the swinging cradle. g

25. In a machine of the vh a scribed, a column or the like having anoverthe,

,tion for the tool with saiddriven shaft, a

hanging head projecting therefrom, a cradle mounted on head to swingthereunder toward and away f inn, a driven tool extending in the and 1ivoted thereabove on the overhangin to swing in the cradle transverselyof the path of swin ing movement of the la :7

for swing ng the cradle therein simultaneously, whereby said profileswork engagec therewith and carried in swinging cradle.

,6, in a machine of the i i M. n W 1, 1'1 scribed, a column or e in:

depending said head an thereon to s t ing towar and column, a tool andswiveled thereabovo on t, overh nging head to swing transversely of thept of swinging moveinontof said cradie, a driven tool mounted theswiveled tool 1' to swing therewi in the cradle and engage workcar rein,means swing W are cradle a1 "1 the tool carrier simnitane v, y, wherebythe driven tool profiles said work.

27. In a machine of the character de scribed, a column or the likehaving an overiginglie c H i on said head to sw rig for i 1 andrearwardly of the machine, plui n tools mounted above the WOLK holderand swiveled on the overhanging head to swing transversely of the pathEng mov" i"- the work holder, means for swingin ,ans for swingingmovement of tools profile work er worli' m5 ri head, aw rl* v head tother A ie machine, a p

i above he we,

3 1.? 9 l. e119 7 O (I head to swing transvorsey oi the in or swingingmovement of the work holder, a driven tool mounted on each of said toolvcan riers to swing therewith, means for swinging the work holder, andmeans for swingin the swiveled tool carriers ant 1 r (T swir "ng moverwheeb-y the driv is h "l w 120 therewith and carried on the work holder.

29.111 a machine of scribed, a column or the li hanging head, a saddlehead, a driven shaft ournaled on a tool swiveled onfthe front of tileO\' hanging. head to swing toward opposite sides of the machine, a'flexible driving connecwork holder mounted on the overhanging head toswing t hereunder transversely of the path of swinging movement of drivetool, and means for swinging said the work holder simultaneously, whereI tool profiles work engaged therewith ca;- ried on the swinging workholder,

30. In a machine of the character scribed, a column or the like havingan overhanging head, a driven shaft journaled on said head, a pluralityof tools swiveled on the front of the overhanging head to sw g towardopposite sides of the machine, 1 ible driving connections for theswinging tools witlsaid driven shaft, a work hold mounted on theoverhanging head to swing transversely of the path of swinging movementof the driven tools, and means for swinging the work holder and thedriven tools simul ancously, whereby said tools profile work engagedtherewith and carried on the swinging work holder.

31. In a machine of the character described, a column or the like havingan over hanging head, a driven shaft journaled on said head, a pluralityof tool carriers arranged in alineinent across the f nt of theoverhanging head and swiveled thereon to swing toward opposite sides ofth machine, a tool rotatably mounted on each of said tool carriers andflexibly connected with the driv on shaft to provice for swingingmovement of said carriers and the driven tools thereon, a cradletrunniened on the overhang head to swing below the driven toolsforwardly and rearwardly of the machine, and means for swinging the toolcarriers and the cradle simultaneously, whereby the tools profile workengaged therewith and carried on t cradle.

32. In a machine of the character described, a column or the like havingan overhanging head extending forwardly thereof from, a driven shaftjournaled on said head, a plurality of mills or cutters arranged in lineacross the front of the overhanging head and swiveled thereon to swingtoward opposite sides of the machine, means for driving the mills orcutters including the driven shaft and flexible connections thereforwith said mills or cutters, a work holder adapted to support a cylinderhead with compression recesses therein of tapered depth, means supporting said work holder on the overhanging head for swinging movementtransversely of the path of swinging movement of the mills or cutters,means for simultaneously swinging the mills or cutters in engagementwith the walls of the tapered compression recesses, and means forswinging the work holder and the cylinder head during swinging move mentof the mills or cutters, whereby the walls of the tapered compressionrecesses are machined and undercut at the deeper portions of therecesses.

nsvaeoe 33. In a machine of the character described, a column or thelike having an overhanging head, a driven shaft journaled on said head,a plurality of tool carriers arranged in line across the front of theoverhanging head and swiveled thereon to swing toward opposite sides ofthe machine, a mill or cutter rotatably mounted on each of the swiveledtool carriers to swing therewith, a flexible driving connection betweeneach mill or cutter and the driven shaft, a work holder adapted tosupport a cylinder head having compression recesses therein of tapereddepth, means supporting said work holder on the overhanging head forswinging movement transversely of the path of swinging movement of themills or cutters, means for swinging the tool carriers simultaneouslywhile the mills or cutters are engaged with the walls of the taperedcompression recesses, and means for swinging the work holder and thecylinder head during swinging movement of the tool carriers, whereby theswinging mills or cutters machine the walls of the tapered compressionrecesses and undercut said walls at the deeper portions of the recesses.

34. In a machine of the character de scribed, a column or the likehaving an overhanging head, a driven shaft journaled on said head, aplurality of mills or cutters arranged in line across the front oftheoverhanging head and swiveled thereon to swing toward opposite sides ofthe machine, means 'for swinging the swiveled mills or cutterssimultaneously comprising an element connected therewith and a cam forreciprocating said element, a work holder mounted on the overhanginghead for swinging movement transversely of the path of swinging movementof the swiveled mills or cutters and adapted to support and swing acylinder head having compression recesses therein of tapered depth, andmeans for swinging the work holder and cylinder head while the swingingmills or cutters engage the walls of the tapered compression recesses,whereby said walls are machined and undercut at the deeper portions ofthe recesses.

35. lln a machine of the character described, a column or the likehaving an overhanging head, a driven shaft journaled thereon, aplurality of mills or cutters arranged in line across the front of theoverhanging head and swivelled thereon to swing toward opposite sides ofthe machine, means for driving the mills or cutters including the drivenshaft and flexible connections therefor with each of said mills orcutters, means for swinging the driven mills or cutters in cluding areciprocating element connected therewith, a cam rotatably mounted onthe overhanging head, and driving connections for the cam with saidreciprocating element, a work holder mounted on the overhanging head toswing transversely of the path of swinging movement of the mills orcutters and adapted to support a cylinder head having compressionrecesses therein of tapered depth, and means for swinging the workhold-er and the cylinder head while the swinging mills or cutters engagethe walls of the tapered compression recesses, whereby said walls aremachined and undercut at the deeper portions of the recesses.

36. In a machine of the class described, the combination of a supporthaving a forwardly projecting overhanging head, a cradle trunnioned onsaid head to swing toward and from said support and beneath said head, aplurality of tools mounted on said head to swing in a plane passingthrough the trunnions of said cradle and automatic means simultaneouslyswinging said cradle and tools.

37. In a machine of the class described, the combination of; a supporthaving a forwardly projecting overhanging head, a cradle trunnioned onsaid head to swing'toward and from said'support and beneath said head, aplurality of tools mounted on said head to swing in a plane passingthrough the trunnions of said cradle, adriven shaft on said head,flexible driving connections between said shaft and each of said tools,and automatic means simultaneously swinging said cradle and tools. 7

38. In a machine of the character described, a support, a cradleprovided at opposite extremities thereof with trunnions journaled on thesupport, a driven cutting tool mounted onsaid support to oscillate on anaxis extending substantially at right angles to a line passing throughsaid trunnions, said cutting tool extending from the support into thecradle and intersecting said line, and means for oscillating the cradleand the driven cutting tool, whereby said tool cuts into and machineswork supported in the cradle to oscillate therewith.

39. In a machine of the character described, a support, a cradleprovided at opposite extremities thereof with trunnions journaled on thesupport, means for oscillating the cradle, a tool holder mounted on saidsupport to oscillate on an axis extending substantially at right anglesto a line passing through said trunnions, a driven cutting tool mountedon the tool holder to oscillate in the cradle and having a longitudinalaxis intersecting said line, and means for oscillating said tool holderand the drivencutting tool during oscillating movement of the cradle,whereby said tool cuts into and machines work supported in the cradleand oscillating'therewith.

In testimony whereof I have signed this specification;

JOHN M. CHRISTMAN.

